# Explaining the Finger Multiplication Table in Base n

• mariouma
In summary, The method described in the conversation allows for quickly multiplying numbers in base n by using finger placement. The number of fingers to the left and right of the lowered finger represent the values for a and b, respectively, in the base n multiplication. This method works because it follows the basic principles of base n multiplication without needing to list all possible cases.

#### mariouma

please i need your help, this question is from my midterm exam ineed solution very quick, it is due next week!
"your finger can provide an (n-1) multiplication table in base n, 2<=n<=10 as follow:
hold n fingers in front of you. to multiply (n-1) by k in base n, lower the kth finger from the left. your answer is (ab)in base n or (b) in base n if a=0, where ab is a string, a is the number of fingers to the left of the finger you lowered, and b is the number of fingers to the right."
explain why this works without listing all possible cases.

We have (n-1)k = nk -k = (k-1)n + (n-k). "a" will be (k-1), and "b" will be (n-k). The number of finger in the left of the kth finger is (k-1), right? So it's "a". And similarly, the number of finger in the right is (n-k), so it's "b".
"nk-k = (k-1)n + (n-k)" comes from the idea that change "-" to "+", because (ab) = a*(n)+b.

## 1. What is the Finger Multiplication Table in Base n?

The Finger Multiplication Table in Base n is a method of multiplying numbers using your fingers to represent the digits in a base n number system. It is a visual and intuitive way to perform multiplication calculations without the use of a calculator.

## 2. How does the Finger Multiplication Table work?

The Finger Multiplication Table works by assigning each finger a value based on the base n number system. For example, in base 10, each finger represents a number from 0 to 9. The fingers are then used to represent the digits in the numbers being multiplied, and the intersections of the fingers are used to determine the product of those digits.

## 3. What is the benefit of using the Finger Multiplication Table?

The Finger Multiplication Table can be helpful for people who struggle with traditional multiplication methods or for those who want to improve their mental math skills. It is also a useful tool for teaching the concept of number systems and place value.

## 4. Can the Finger Multiplication Table be used for any base number system?

Yes, the Finger Multiplication Table can be used for any base number system. The number of fingers used will depend on the base number system being used. For example, in base 8, only 8 fingers are needed, while in base 16, 10 fingers plus 6 intersections are needed.

## 5. How accurate is the Finger Multiplication Table compared to traditional methods?

The Finger Multiplication Table is just as accurate as traditional methods of multiplication. However, it may not be as efficient for larger numbers or complex calculations. It is best used for simpler calculations and as a supplementary tool to traditional methods.